REV96883

• Permit No: C1980007
• IBM Index Class Name: Revision
• Doc Name: APPENDIX 3 MINE RECLAMATION STUDY SECOND ANNUAL REPORT
• Type & Sequence: TR53
• Media Type: D
• Archive: No

on north than south aspects (Section 3.4), which suggests that maxi-
' mining north aspects on areas to be revegetated is an important consi-
• , deration.
3.4 ReveRetatioa Species Performance - Grasses and Forbs
3.4.1 General Comparisons
The following discussion presents the results of the second growing
season for this experiment, Topics discussed include general growth
trends over time, as evaluation of species performance during the second
year, and relative growth of test species in relation to the treatments
applied.
The growing season climatic pattern for 1979 was very similar to
that experienced in 1978 (Section 3.1.1). It consisted of abundant
winter and spring moisture and a dry, warm summer. Average canopy cover
of planted species declined from 9.8x in Hay to 7.4x in September
(Table 3.4-1). Volunteer weeds showed a much greater decline (17.6°,~ to
7.7x). This decline is attributed to the withering of annual species
such as cheatgrass (Bromus tectorum), Japanese brome (Bromus japoaicus),
and penaycress (Thlaspi arvense). Five treatments (4BCMN, LBEHR, LBEXR,
2$CHN, and 2BEX5) showed as increase in planted species cover between
•~ Hay and September. In Hay maximum canopy cover (25.4x) was recorded for
4DSXN; least cover ( .lx) was recorded for 2BEXS. Ia September maximum
planted cover (22.8) was recorded £or LBEXR; least cover (Ox) was
recorded foz 4BCHS and 2BCXS. Average planted species cover for fall
1979 (7.4°,~) was little different from that in 1978 (7.7x).
Average planted species density for all treatments in May was 15.7
plants/.5m2 (2.8 plants/square foot), a sharp decline from 20 plants/-
square foot in 1978 (Table 3.4-1). Haximum density (82) was measured
for 4-SXN; minimum density (.5) was recorded for 2BEXS. Average volun-
teer species density was 152.4/.Sm2, indicating that volunteer species
greatly increased in density over 1978, when average density was
16/.3m The data suggest that weeds provided substantial competition
to planted species for soil moisture and nutrients during 1979.
Average 1979 planted species production for all treatments was
l3.5gm/.5m2 (241 lbs/acre); volunteer species production was 14.7gm/m2
(262 lbs/acre). These data and density results show that although weeds
~ occurred at a much higher density than planted species, the production
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